Where is an onomatopoeia in Harry Potter and the Prisoner of Azkaban?

One example of onomatopoeia in Harry Potter and the Prisoner of Azkaban is in Chapter 11, "The Dementor." When Harry is in the Shrieking Shack and encounters Sirius Black, there's a moment where:

> ""Bang" went the door as it slammed shut."

The word "Bang" imitates the sound of the door slamming, making it an onomatopoeia.

Let me know if you'd like to find more examples!